Neanderthal

by Paul Jordan

  The heavy brow-ridges, swept-back cheeks and broad nasal base of the Neanderthal face.

  A teaching model of a Neanderthal skull illustrates, along with brow-ridges and bun, the mid-face prognathism and chinless right-angled lower jaw of the type.

  For the whole mid-face of the Neanderthal type was, as it were, pulled forward, as though one had got hold of the nose and somehow stretched the face towards one on the median line running from the ‘chin’ to the gap between the eyes. This prow-like mid-face is really the most distinctive feature of the Neanderthal countenance, after the brow arches. The pulled-forward mid-face resulted in an appearance of swept-back cheeks and eye sockets that is simply not seen in any modern people, an effect made more obvious still by the lack of any hollowing in the cheek-bones above the eye-teeth (called canine fossa) of the sort that we display. It has been suggested that the inflated and swept-back cheeks might have reduced the chances of frostbite in freezing winds, but modern dwellers of the frozen north do not exhibit this condition. And it should be noted that the ‘mid-line prognathism’ of the Neanderthal face is not the same condition as the projecting mouth and teeth region seen in some people today, which does not involve the whole face, cheeks and eye orbits. The Neanderthal nose was evidently huge, with large nostrils as indicated by the low floor of the nasal opening. This represents another departure from the Eskimo pattern, where narrow noses conserve internal heat and moisture in the dry cold conditions of the north today. The big Neanderthal nose has been proposed on the one hand as a mechanism for heating air in proximity to the brain’s blood supply and, on the other, as a cooling radiator for people working hard, harder perhaps than anyone does today, and in danger of overheating inside in externally cold conditions. On both accounts, the nose is plausibly seen as some sort of adaptation to a hard life in the cold, until one recalls that ancestral Neanderthalers of the warm interglacial period before the last ice age also displayed the large noses.

  The Neanderthalers’ typical retromolar gap.

  The mouth and throat region of the Neanderthal type has been of particular interest to anatomists since it promises to throw some light on the Neanderthalers’ physical capacity for speech. It may not be possible, on the basis of brain details as evidenced by the interior form of their skulls, to draw firm conclusions about speech capability in any sorts of fossil men, so study of throat and mouth conformations at least opens up the possibility of determining whether the Neanderthal people, for example, were physically capable of speech (always supposing they were mentally disposed to it). Apes can be taught to wield a certain amount of ‘linguistic’ ability (how much is a matter of controversy) in the form of sign language, but only with the greatest difficulty can they be encouraged to utter even a very few more or less recognizable words like ‘mama’, ‘papa’ and ‘cup’. The truth is that they are simply not physically equipped to come out with a range of consonant and vowel sounds. In the wild, chimpanzees employ a repertoire of a dozen or so calls with absolutely no signs of anything we might call a pre-language tendency.

  Neanderthalers were a very long way from chimpanzees, with admittedly distinctive but none the less basically modern human skeletons and full-sized brains. They made a range of tool types and thrived in very adverse conditions, with a panoply of behavioural accomplishments that included co-operative hunting and burial of the dead. The use of language, though it might well have been less complex and developed, looks like a certain Neanderthal attribute. But in the past, and not just in the nineteenth century with people like Boule, serious doubts have been raised as to Neanderthal Man’s physical capacity for speech. We are able to produce the large range of consonants and vowels that we do because our vocal tract is a complicated instrument with several components acting upon each other. The basis of the system is the larynx, the voice-box containing the vocal cords, originally evolved in our remote animal ancestry perhaps to prevent food from getting down into the lungs. Above the larynx is the supra-laryngeal tract consisting of the section of windpipe called the pharynx and then the oral and nasal cavities. Sounds are produced as air is forced through the closed vocal cords, vibrating at different frequencies with different degrees of force of air and closure of the cords. Clearly breath control is a basic factor in producing the sounds, requiring complex nervous regulation of the chest muscles – it has been thought that older forms of man like Homo erectus may have been deficient in this respect, judging by the size of the holes in the thoracic vertebrae through which nerves controlling breathing pass, but the Neanderthalers were as well endowed in this area as ourselves. The various frequencies of sound produced by the vocal cords are extensively modified thereafter by tongue position, by routing or not through the nose, by opening or closing the mouth in conjunction with different lip shapings. Tongue control seems to have been as well developed in even Homo erectus (or at least the latest manifestations of the H. erectus type) as in Neanderthal and fully modern people: the hypoglossal canal through which pass nerves to the tongue is as capacious in 400,000-year-old fossil men as it is today, providing similar capacity for tongue control in speech, but the Australopithecines of a couple of million years ago show no more nervous provision for tongue control than do the chimpanzees.

  The differing vocal tracts of the Neanderthalers (left) and moderns (right).

  In modern humans the supra-laryngeal tract is long, with much scope for subtly modifying the sounds coming off the vocal cords, by virtue of the low position of the larynx itself in the throat (lower than in the apes). With a low-placed larynx, the pharynx is almost as long as the oral cavity above it and these two compartments, at a right angle to each other, offer in combination many opportunities for sound modification. In the Neanderthalers, judging by the conformation of their skulls and jaws, the windpipe section was not as long in relation to the mouth cavity as it is in moderns and the conjunction of these two parts of the supra-laryngeal tract did not form so much of a right angle; these effects were exaggerated by reconstructions like Boule’s that made the Neanderthal skull base too flat and put the larynx too high in the throat. This in turn suggested a reconstruction of the shape of the hyroid bone of the back of the throat (the human body’s only free-floating bone, not articulated with any of the rest, and – until the 1980s – never recovered among Neanderthal bones) that would have rendered Neanderthal Man not only incapable of forming several important vowel sounds, as the protagonists of this reconstruction hoped to demonstrate, but also of swallowing or even opening his mouth. When a Neanderthal hyroid was eventually found, it turned out to be just like a modern one. It probably remains true, all the same, that the Neanderthalers were not as subtle in their vowel distinctions as we are and perhaps could not utter the G–K consonantal sounds either. It might be thought that this would not matter very much, since modern human speech covers such a wide spectrum of sounds, with many vowels unstable in pronunciation, but it is possible that even slight ambiguities of speech, slightly greater difficulties of interpretation in tricky hearing situations, might have helped to take the competitive edge off the Neanderthal people if and when they found themselves on the same patch as more fully modern humans. There are certain vowel sounds that all known languages like to keep stable and, it has been contended, these may have been beyond the powers of the Neanderthalers. In short, physiology does not deny the Neanderthalers a voice, but it holds out the possibility that that voice was not quite as useful as our own, and as yet it has little to say about the mental capacities that might have driven any Neanderthal speech.

  It is possible to imagine an evolutionary scenario in which the achievement of the fully modern sort of human skull shape and vocal tract went hand in hand with the development of language capacity and improved technology. Better tools and better cooking methods might be seen to reduce the Neanderthal use of the mouth as vice or shears or hide-scraper, doing away with the need for heavy jaw and face with brow-ridges and bun, shortening the skull and allowing the skull base to arch upwards
to a greater extent, permitting the extension and angling of the pharynx, enhancing powers of speech, putting a premium on individuals who could speak well and think well, promoting the incidence of clever people in the population, leading to the adoption of better technology, doing away with the need for heavy jaw and face . . . and so on, in an interactive feedback that led from something like Neanderthal Man to ourselves. But to many it looks increasingly as though the unique idiosyncrasies of the Neanderthalers mark them off as a European peculiarity of the story of human evolution and that we evolved from people who, while they were once at the same general stage of evolution as the Neanderthal type, were not themselves distinctively Neanderthal. Still, something like the feedback process just described must have happened to those direct ancestors of ours.

  The back of a Neanderthal skull, showing the depression of the suprainiac fossa where neck muscles were attached.

  There are further detailed idiosyncrasies of Neanderthal anatomy, like the suprainiac fossa at the back of the skull, where neck muscles were attached to a depression rather than the protuberance commoner in other forms of humanity, the large juxtamastoid process (in relation to the mastoid) where the muscles of the lower jaw were anchored and details of the inner ear, that both mark out Neanderthal Man’s distinguishing features and help us to trace them back into general human evolution. Those distinguishing features, as we shall see, evolved over time and not all at the same time, and were less in evidence even among the immediately ancestral Neanderthal types of the last interglacial period before the ice age heyday of the classic Neanderthalers.

  The adult male Neanderthaler from Amud.

  Those less-than-classic Neanderthalers have been dubbed ‘generalized Neanderthal’ and ‘progressive Neanderthal’. The people of Krapina belonged to this grouping: they were more lightly built and their faces, though large, were more lightly made, sometimes with higher foreheads, while their limb bones were more like those of moderns, less stout, less curved. But they were unmistakably Neanderthal in their projecting mid-faces, their taurodont teeth, their retromolar gaps at the back of the mouth, their barrel chests, their brow arches and buns at the back of their heads. While the classic Neanderthal type is associated with the last ice age and most individuals of the type probably lived between about 80,000 and 50,000 years ago (though there are some important finds of later dates), the Krapina people were probably living at around 130,000 BP (Before the Present), at the end of the last interglacial or during a warmish interstadial after the slow onset of the last ice age. Similar dates and earlier ones apply to other finds of this more generalized type. In the Near East, even within the period of the ice age but well away from the glaciers of course, there are some non-classic Neanderthalers who do not so much look back to the generalized Neanderthal type of the last interglacial as (conceivably) forward to modern humanity. The tall (for a Neanderthaler) and big-brained male of Amud in Israel, though massive of jaw, exhibits relatively light brow arch development and less inflated cheeks, with a larger mastoid process than most Neanderthalers show and something approaching a chin. The cranium, though long in side view and globular from the back, has not the rear bun that classic Neanderthalers sport like a counterbalance to their heavy faces. Some details of the Amud skeleton are matched in other finds, both of early and late ice age date, from Israel and Iraq.

  The evolutionary relationships of all these Neanderthal types with each other and with both our common ancestors of earlier times and ourselves has always been a matter of fierce debate. We have seen the widely varying interpretations of the Neanderthalers in the nineteenth century, ranging from Neanderthal as direct ancestor of modern man to Neanderthal as simian byway of human evolution – from father and mother to hardly a cousin. The debates of the second half of the twentieth century have been even more acrimonious, with good work, sound points and plausibility on both sides of what is essentially the same argument as that between Schwalbe and Boule. Anatomical comparisons of specimens, dated as closely as can be, can only get us so far. We can arrange the meagre fossil material we have on genealogical lines of possible descent, with informed conjectures as to how one form might have evolved into another. We have seen that a picture can be built up of reducing faces, flexing skull bases, better brains and improved vocal tracts, all interacting with culture and technology, to promote rapid evolution from something like a Neanderthaler into modern man. A biological process known as neoteny has been advanced as another mechanism by which modern man might have evolved out of something like a Neanderthal type: neoteny sees an immature stage of a creature’s life cycle become capable of reproduction without ever reaching the adult form seen previously in its ancestors. There are numerous examples of neoteny at work in zoology and it has been suggested that slender, smooth-browed, mentally adventurous modern humanity might have evolved quite quickly out of heavy, big-faced, stick-in-the-mud Neanderthal Man, when natural selection favoured the fresh type. There are detailed reasons, both on biological grounds and arising out of study of the record of fossil man, why this idea has not continued in favour, but speculation like it is inevitable and only right and proper while we are faced with making sense of our fossil record of a relatively few bones from sometimes doubtfully dated contexts. So the application of genetic studies to the problems of human evolution and the human fossil record has been welcomed by many anthropologists and archaeologists (if not by all those with a talent for comparative anatomy) as a way of taking the study of our ancestry on beyond what the physical comparison of the bones can tell us. We shall see later that genetically grounded estimates of the dates of various phases of human evolution, arrived at by genetic analyses of modern human populations, have been the basis of much contention among anthropologists in recent years. Meanwhile, direct genetic work on Neanderthal remains has also produced dramatic results to date, with the promise of more to come. And so we are able to round off our characterization of the Neanderthal physical type with some details of these people’s genetic type too.

  Aptly, it is upon the very bones of the original Neanderthal Man that the first published work on Neanderthal genetics has been done. The upper arm bone of the skeleton from the Feldhof cave in the long since vanished Neanderthal, kept these 140 years in Bonn Museum where Schaafhausen first examined it, was recently tested to see if enough mitochondrial DNA (mtDNA) was left in it to allow the extraction of genetic information. Thanks perhaps to the long preservation of the specimen in the mud of the cave and then to the varnishing by Fuhlrott and Schaafhausen, the bone turned out to make some genetic determination feasible. About one-fortieth of the entire sequence of every cell’s mtDNA, 378 bases of mitochondrial DNA, was available for study in comparison with the same sequence of modern humans and chimpanzees. Within this run of the sequence, modern populations show variations among themselves at up to about eight places, with chimpanzees differing from humans at some fifty-five places. The mtDNA from the Neanderthal revealed variation from the average modern count at twenty-seven places, markedly more than the widest range of variation among modern peoples and halfway to the chimpanzee rate of variation. On the strength of this degree of variation, the geneticists who did the work concluded that Neanderthal Man was not at all closely related to us, and that indeed his line might be calculated to have diverged from our own at about 600,000 years ago – before Neanderthal or modern forms of humanity had distinctively evolved out of the lattermost manifestations of Homo erectus.

  It may not be so easy to extract mtDNA from other specimens of Neanderthal Man or other early humans; the important Neanderthal finds from Israel, for example, preserved in much warmer circumstances, may not afford the necessary organic material without loss and contamination. So this particular approach to the genealogy of the Neanderthalers might be limited, with only a few instances among the hundreds of fossils where information is forthcoming – but even a few instances will certainly throw much light on the question of the relationship between Neanderthal and modern humanit
y. If further mtDNA determinations (and it seems that the Krapina and Gibraltar remains are already under study) confirm the distancing of the Neanderthalers, both classic and generalized, from modern types, then the tendency of both comparative anatomy and archaeology to remove the Neanderthal people from the line of our descent will be reinforced. But the situation is a complicated one. There always remains the possibility that some modern people might turn out to carry more of the Neanderthal sort of mtDNA sequence than any so far tested (and the tested sample is not that large, inevitably). There is the distinct possibility that the Neanderthal people themselves showed a considerable variation in their mtDNA constitutions. And it must always be remembered that mtDNA only charts one line of genealogical inheritance in the cells of the human body; the same cells also carry nuclear DNA that has come down by other lines of descent and it may be that, while modern humanity carries no distinctively Neanderthal pattern of mtDNA inherited from Neanderthal women, we may display a partly Neanderthal inheritance in our nuclear DNA. Studies of worldwide variation in DNA patterns, especially of mtDNA, have in the last decade been used to suggest that modern humanity everywhere is all descended from a relatively small population of modern Homo sapiens sapiens individuals who evolved in Africa by ‘about 100,000 years ago’ and then spread all over the world, replacing (by fair means or foul) all pre-existing local populations of Neanderthalers or late Homo erectus or whatever. The date at which all this might have happened has been disputed even among proponents of the theory, but is largely based on estimates of the rate of mutation, of mtDNA in particular, that might have produced the current variations in human populations today. We shall return to this topic later – for the moment, it is enough to note that Africa is often nowadays posited as the cradle of modern humanity, not so much because it has a clear and well-dated fossil record of evolving forms as because its modern peoples show more genetic variation than do people in the rest of the world, suggesting that African moderns have been there longer (and in larger numbers) than modern types anywhere else, with more time and numbers in which to develop and maintain more mutations, whereas in the rest of the world we are all descended from small numbers of moderns who spread out of Africa after the modern type evolved there, with less time for accumulated variations. Much can and, needless to say, has been said about the assumptions and methodology that underpin this idea and its dating implications, as we shall see.